The invention refers to the field of medicine, specifically to that of orthopaedics and, and exactly to spinal surgery, and is used for treatment of diseases and injuries of the spine in specialized departments of vertebrology and neurosurgery.
An implanted device for spinal fixation is known, comprising a screw for spongy bone bearing an improved saddle-shaped configuration fixed in a place with a nut and comprising a simple and effective locking mechanism having some pins, each of them contacts with an upper half-saddle and a nut to prevent rotation of the latter with respect to the rest of the configuration. The implanted system also comprises rods, rigidly caught by the saddle-shaped configuration and a sublaminar wire, where the rod/wire interface is protected with a wire tread (U.S. Pat. No. 5,030,220. IPC5 A 61 F 5/04, A 61 F 5/00).
A rod screw is known as well as a device for correction and fixation with that kind of a screw, in which the rod screw has a threaded part and a spherical segment or a head, on the latter a packing is set with a connecting element to set a rod, and the connecting element and the packing are connected with each other in such a way, that the distance between its end and the connecting element can be changed (International Application N WO 91/06254. IPC5 A 61 B 17/60).
A device for spinal treatment is known, comprising junctions of vertebral fixation with curved needles, connected by straight screws with each other, and two units, which are connected with central plates, on which straight needles are fastened with the help of plates held down and screws (Author Certificate/A.c./1537237, A 2, USSR. IPC5 A 61 B 17/60). In the known device the central plates are made as a semicircle, supplied with holes and cut-outs. Moreover, vertebral fixation is performed using curved needles inserted into the spinous process and straight needles inserted into vertebral body.
A technique of modeling closed insertion of fixators into the vertebral body is known, comprising its stabilization by insertion of wire-markers in the spinous process in the middle sagittal plane, after that, displacing from it at first in the cranial and then in the lateral direction the fixators are inserted into safe zones from backward forward at an angle to the sagittal plane, and their direction is marked on a template, which is then used during insertion of the fixators (U.S. Pat. No. 2,093,901, C1, RF).
A technique for insertion of a threaded rod in vertebral body is known as well as a device for this implementation (U.S. Pat. No. 2,051,633, C1, RF). The essence of the invention is in pre-insertion of a guiding axial wire, a guide with a central longitudinal hole, a protective tube, with the help of which protection of soft tissues is made, direction and depth of the threaded rod implantation are controlled, for this a device for osteosynthesis is used provided with a rotation mechanism as a case, including a ratchet with a lock, a quadrangular jack with a ball fixator on one end and a handle with circular recesses, set on the opposite end perpendicular to the case.
A compression-distraction device is known, including rings and arches, wire fixators, tie screws, spherical hinges, fixing elements, in which each pair of the tie screws is connected by the spherical hinge, and the rings and arches are set at a regulated distance from the plane of the hinge arrangement (A.c.374076, USSR).
A device for fixation and correction of the spine is known, comprising threaded rods and a base, provided with lever ties (U.S. Pat. No. 2,019,148, C1, RF). There are longitudinal threaded bars in the known device, each of them is made being consisted of three parts, connected with each other by hinges and provided with rod holders as a cylinder with a fixing element and a slot, thereby the parts provide multi-planar transport of the threaded rods.
A device for treatment of spinal curvatures is known, in which two support junctions are connected with each other by a reposition junction, using threaded rods of distractors (A. c. 1781872, A 1, USSR). The reposition junction has two cross-pieces, connected with each other by hinges and with the help of rods respectively with plates. A shackle with a stud is set on one of the threaded rods; a flexible traction, fixed to the spine in the apex of the curvature, is attached in the transverse hole.
A device for treatment of scoliosis is known, comprising staples with holes and a slot, attached to them support elements and fixation elements, in which one of the staple ends is deviated along the plane to its convex side, a fixing plate with L-reversed section is arranged on the staple with the possibility of its transport along the slot and fixation; a slider is on one of its wall, it is sunk into the staple slot and becomes an axle, in the top of which, in its turn, a threaded pole is made, and a slot, parallel with the staple plane, is made in the other wall of the fixing plate, a tractor is set by hinges on the axle of the fixing plate, its threaded end is attached to the deviated end of the staple through a face support, bone rods and clips are in the slots of the fixing plates with the possibility of transport and fixation, the latter consist of two arched plates with tenons, connected by a tie bolt at their base, and the staples are connected with each other with the possibility of their interlocation change and fixation by use of hinge bars (U.S. Pat. No. 2,086,202, C 1, RF).
A device and a technique for spinal extrafocal osteosynthesis are known, the device comprises threaded rods, support elements, screw tractions and fixing elements, the support elements in the device are made as arched plates with curvature radius 140xc2x110 mm and longitudinal slots, in which the threaded rods are fastened perpendicular to the plane of the support plate, the threaded rods are to be inserted in vertebral bodies, free movements are made within 30xc2x0-range with respect to the support plate at the expense of compensatory washers, the support elements have free movements within 60xc2x0-range and are connected with each other by posts with the compensatory washers and the longitudinal screw tractions in two parallel planes. In the technique of spine extrafocal osteosynthesis by transpedicular insertion of the threaded rods in bodies of some adjacent intact vertebrae with attachment to the external support transpedicular fixation is supplemented by fixation of spinous process, in an involved vertebra the rods are inserted directly in the body, omitting the arch, and two adjacent vertebrae are fixed by a single support plate, for example, the involved vertebra and the one below, thereby creating repositional moment of forces at the level of the most involved spinal motor segment (Application N 96113284/14, A, RF, Publ. 10.27.1998.).
ESSF device is known, which has transverse beams, made integral and provided with apertures to set ball hinges with lock screws (Weber B. G., Magenl F. The external fixator. AO/ASIFxe2x80x94Thread Rod System Spinexe2x80x94Fixator. Berlin: Springer-Verlag, 1985.xe2x80x94P. 298-300). The transverse beams are connected with each other by threaded rods and the ball hinges. All the threaded rods have antirotational thread. In the device Schanz screws are used, which are connected by the transverse beams, using screw clamps. Slots, made in the transverse beams, give the possibility to change transverse distance of the Schanz screws.
However, the design of the device mentioned above doesn""t allow to correct spinal deformities and exactly scoliosis of Grade III-IV, because setting the ball hinges in the transverse beam apertures limits its use versatility due to absence of the possibility of setting ball hinges, oriented to the deformity apex.
A device is known for infusion of medication solutions into bone and soft tissues, comprising a case with a tubular needle, a union for solution feeding in and a mandrin with a cone plug and a handle, set with the possibility of rotation around the axis, a longitudinal groove and as a perpendicular to it narrowing capillary gap are made on its mandrin cone plug, the mandrin with the needle form a throttling valve, the flow section of which is the same as the cross-section of the longitudinal groove (A. c. 858839, USSR. IPC3 A 61 M 1/00).
A device is known for intraosseous injections, comprising a handle with a longitudinal canal and a slot, a separable needle, set on the handle, a mandrin with a slider, set with the possibility of transport in the handle and needle canals, and a fixator of the mandrin position, in which a handle is provided with two stops at its ends, the fixator is set on the stop of the handle working end and the shape of the handle working end conforms with the shape of the mandrin working end (A. c. 914063, USSR. IPC4 A 61 M 1/00).
However, the design of the device mentioned above is intended for independent use and it is not provided for its use in combination with the vertebral fixation element.
A clamp is known, comprising two handles, connected by hinges, with rings and a rack-and-pinion lock and working jaws, where the working jaws are made with cheek-pieces and slotted bottom, moreover, the closed slots form a round hole (A. c. 850064, USSR. IPC3 A 61 B 17/18).
However, design of the working jaws doesn""t allow to use the known clamp for insertion of the fastening end of the vertebral fixation element through soft tissues to vertebral body.
A device for scoliosis treatment is known, comprising supports, set in parallel and interconnected, on which elements of vertebral fixation are fastened, in which each support is made as a plate, provided with connecting shanks, the latter are fastened in posts, set with the possibility of transport in slots of schwellers, moreover, each preceding support is connected with each following one with the possibility of transport (Certificate 1797 for utility model, RF. IPC6 A 61 B 17/60).
A correcting device for the spine is known, comprising a unit of vertebral fixation, which is made from a support as two bars, connected with each other by a central support element and at the ends, having lateral support elements. In the longitudinal slots of the bars clamps with vertebral fixators are set (U.S. Pat. No. 2,128,021, C1 RF. IPC6 A 61 B 17/66, 17/70).
However, the design of the known devices hasn""t sufficient stiffness due to the fixation junction, having a large number of built-up elements.
It is an object of the present invention to design a device for external transpedicular fixation of the spine for correction of its deformities and injuries, an instrument for insertion of the vertebral fixation element, and a technique of their use for treating deformities and injuries of the spine.
The object is achieved due the fact that in the device for external transpedicular fixation of the spine, comprising not less than 6 fixation junctions connected with each other through ties into support units connected through threaded rods capable to produce mutual transport and indirect effect on intact vertebrae, into each of said vertebrae the working ends of two vertebral fixation elements are inserted while the fastening ends of said fixation elements are secured with clamps in each said fixation junction provided with holes, there are not more than 9 fixation junctions fastened by ties in threes as three support units, two of them are outer and one is intermediate, each of them is connected with the other with the possibility of spatial transport with the help of not more than 6 distraction rods, the ends of each out of three distraction rods are indirectly connected with one of the fixation junctions of the outer support units and correspondingly with the fixation junctions of the intermediate support unit, moreover, each of the fixation junctions is made as a figure plate having a transverse axis of symmetry and provided with symmetric through longitudinal slots located between a central bulge and ends made as a prism while the central bulge and the prism-shaped ends are provided with connecting holes and fastening elements, moreover, to each of the fixation junctions not more than two elements of vertebral fixation are attached by clamps, said elements are made as half pins, each of them has a working end made cone-shaped and provided with screw-shaped thread limited by a stopper and a fastening end on which a flattening is made supplied with a through hole, the axis of the latter is perpendicular to longitudinal axis of the half pin.
Preferably, each of the fixation junctions is made as a figure plate shaped as an isosceles trapezium and, respectively, a transverse axis of symmetry of the plate provided with symmetric through connecting holes, the axis of each of the latter is perpendicular to the transverse axis of symmetry and the connecting holes are made in the middle and at the ends of each plate, moreover, each of them is provided with two pairs of through mounting slots made at angle 35-40xc2x0 on both sides from the transverse axis of symmetry of the plate and in said slots, in one out of the pair, one element of vertebral fixation is fastened made as a half pin; the outer support units are connected with the intermediate one by connecting hinge junctions, each of them is assembled from interconnected posts and each of the said posts is provided with distraction rods.
Such an implementation of the fixation junctions of the mentioned device allows to increase fixation rigidity of intact vertebrae using the elements of their fixation, fastening ends of which are oriented at angle 35-40xc2x0 with respect to the spinal longitudinal axis, and to regulate an adjustment of the fixing site of the fastening ends of the elements of vertebral fixation in view of applied distraction forces.
Simultaneously, the object to achieve infusion of medication solutions in the bodies of vertebrae is solved during their fixation in the process of treatment due to the fact that each half pin is provided with a longitudinal slot made all over the half pin length, and in the slot an injection needle is fixed in which a cannula provided with a plug is set from the direction of the fastening end of the half pin.
To provide complete correction of spinal deformity both in trauma and Grade 3-4 scoliosis cases it is preferable to embody each of the connecting hinge junctions as a ball head and a hollow sphere, both having cylindrical bulges with holes, while the ball head is set on the truncated and opposite to the cylindrical bulge side in a hollow sphere the inner surface of which is covered with antifriction coating; distraction rods are set in the holes of the cylindrical bulges; the truncated part is equal to ⅓ of the hollow sphere and the angle of the truncated part in projection is 90xc2x0; moreover, the ball head is provided with recesses and the hollow sphere with a hole, the axis of which is perpendicular to the axis of the hole of the cylindrical bulge in which a lock is set.
Moreover, each of the connecting hinge junctions can be made as a distraction rod provided with a ball head on one of the ends, the head is set in a sleeve connected with a ball pivot made on one of the ends of the second distraction rod.
In a variant of the invention implementation the device can be provided with a microschweller, on one plane of which a longitudinal slot is made and at least two mounting holes on each side from it, the microschweller is connected with the outer support units through two posts and threaded rods, and it is connected with the intermediate support unit through a lug with a threaded shank with the possibility of transport in the sagittal plane.
The embodiment of the device with such kind of traction provides an additional effect during correction of a lateral spinal deformity and increases the design rigidity.
To prevent slipping of the vertebral fixation element during its fastening on the fixation junction each of its fixation clamps is preferably made as an angular post embodied as a cylinder with threaded surface and connected at an angle with a prismatic head having a cylindrical deepening into its inner surface from the side of the cylinder, the axis of the deepening is perpendicular to the axis of the cylinder on which conical and spherical washers can be set.
According to the invention a technique of usage of the device for external transpedicular fixation for correction of spinal deformities and injuries has been developed, including percutaneous insertion of the vertebral fixation elements into vertebral bodies and fastening of the elements in the fixation junctions for subsequent application of distraction forces in the damaged area of the spine in which a laminectomy and discotomy of cranially and caudally located spinal discs at the deformity apex are performed, autografts are inserted into the cavity of each disc, the intact vertebrae above and below are fixed using the elements of vertebral fixation, which are inserted into the centre of each arch at the angle 30-45xc2x0 to the sagittal plane which passes through the axis of each vertebra, after that the spine is gradually corrected to biomecanically normal position by graduated transport of the support units using connecting elements, and, respectively, of the intact vertebrae located above and below the area of surgical intervention.